Ball or plug valve stem extension and lock mechanism

ABSTRACT

A fluid control valve stem extension and locking device includes a rod member to extend the valve stem with a lower end bored and threaded to threadably engage the exposed end of the valve stem with set screws extending horizontally into the bore opening to bear on the sides of the valve stem, the upper of the extension rod shaped to duplicate the shape of the exposed end of the valve stem and a detached plate having a hole shape to interfit over the exposed end of the valve stem coupled to move with turning of the valve stem and including a stop device duplicating the function of the stopping device used in the valve with a locking mechanism including a cylindrical tube sized to interfit over the stem extension device with an attachment plate structurally attached to the lower end of the tube with a horizontal radial plate structurally attached to the outside surface of the upper end of the tube with two holes corresponding to the valve positions and a locking plate with an opening to interfit over the shape at the upper end of the rod to couple with and move in conjunction with the turning of the valve stem and having a hole to align with either of the two holes in the radial plate and receive a pad lock.

This application is a division of application Ser. No. 07/069,876, filedJuly 6, 1987, now U.S. Pat. No. 4,756,507, dated July 12, 1988.

BACKGROUND OF THE INVENTION

This invention involves fluid control ball or plug valves and valve stemextensions to allow the valve to be turned free of obstructions locatedclose to the valve body.

Fluid control valves continue to be the most troublesome of continuingmaintenance and performance problems in any systems utilizing fluidflow. For example, most of the maintenance problems in a chemicalmanufacturing plant or a power plant involve valves in some way or theother. With emphasis on energy conservation, it is now standard practiceto insulate most piping systems which are running above or below ambienttemperatures. When the insulation is extended to cover the valve body,special arrangements must be made. It is not usually practical to coverup the handle or the wheel used to turn the valve stem to open or closethe valve. Valve extensions have been provided in various configurationsto extend the handle or wheel to a position outside of the insulation sothat the valve can be opened or closed without disputing the insulationcovering.

This invention is directed to ball or plug valves, wherein a one-quarterturn of the wheel or handle changes the flow from full "on" to full"off" in that direction. The valves may be two way, three way or evenfour way valves. The two way valves have a single flow bore through theball or plug, while the three way have a "T" shaped bore to provide athird path.

Prior stem extensions such as those supplied by Jamesbury Corporation,of Worcester, Massachusetts and by Watts Regulator Industrial ProductsCompany of Lawrence, Massachusetts and extensions described in U.S. Pat.Nos. 3,582,116 to Steven A. Young and 905,172 to R. S. Goodsonillustrate extensions that utilize bolts and attachment mechanisms thatdo not provide convenience combined with the necessary durability forindustrial use. The loosening of disengagement of a valve extension evenafter months or years of operation causes a severe safety hazardparticularly when high temperature fluids or toxic chemicals are passingthrough the valve system. A typical Jamesbury extension is welded intoplace and cannot removed on line.

An additional problem involves the necessity of locking the valves inposition, either in an open position or in the closed position. Again,because of safety considerations, such as when maintenance is beingundertaken on the line, it is typically absolutely necessary to preventunauthorized changing of the valve closure position. A number of lockingmechanisms are provided in the industry to prevent unauthorized openingor closing of control valves, but the use of insulation on the pipeswith a valve stem extension poses problems and needs not satisfied bythese prior devices. It is necessary to provide a locking mechanismwherein the valve handle may be locked in either an open or a closedposition without disrupting the insulation when the valve closure is tobe changed. Further, it is important that water and other fluids cannotpenetrate along the valve stem extension into and under the insulationto cause corrosion or other maintenance problems for the valve and theinsulation covering.

None of the prior art devices satisfy these needs or attain the objectsdescribed herein below.

SUMMARY OF THE INVENTION

This invention is used in conjunction with a fluid control valve havinga body, a value stem having an exposed end on which a valve turningdevice detachably attaches. The valve stem rotates the valve stem toadjust fluid flow through the valve and a stopping device is included tostop rotation of the valve stem in a full open position to open thevalve and in a closed position to close the valve. Typical valve turningdevices are handles, wheels and motor driven mechanisms. Typicallystopping devices are metal tabs extending either outwardly horizontallyfrom the valve stem or outwardly and downwardly to engage a pair ofstops, usually molded into the valve body. The invention is a valve stemextension device including a rod member, preferably a circular rod,having an upper end. The rod member is of sufficient length to positionthe valve turning device now attached to the upper end of the rod memberat a position to move free of any obstruction, such as insulationsurrounding the valve. The rod member has a lower end with a boreopening into that end having a female mating shape of a cylindricalthreaded bore having threads mating to the exposed end of the valve stemwith two set screws threadably engaged through horizontal holes in theside of the rod member opening into the bore opening to bear on the endof the stem mated into to the bore opening. The upper end of the rod isa shape to sufficiently duplicate the shape of the exposed end of thevalve stem to allow the valve turning device to be securely fastenedthereon. Preferably, when the stopping device is structurally attachedto the valve turning device, the device further includes a plate havinga hole of a shape to interfit over the exposed end of the valve stem andcoupled with that exposed end to move with turning of the valve with theplate further including a stop device duplicating the function of thestopping device of the fluid control valve. The preferred shape of theexposed end of the valve stem is such that if a member with a hole ofthat shape is interfitted over the exposed end and the member is turned,the valve stem will turn. It is particularly preferred that the exposedend of the valve stem be threaded.

The device of the present invention is preferably connected to valveshaving a threaded exposed end of the stem. It is further preferred thatthe exposed end of the stem be rectangular in cross-section and bethreaded on at least two vertical sides having at least one flat side.It is most preferred that the present invention be connected to valveshaving an exposed end of the stem having two vertical flat sides andwith the device having two set screws engaged through the side of therod to bear on the opposite flat sides of the exposed end. It ispreferred that the device include a wide flexible water shed, annularelastomeric washer snugly interfitting onto the rod member of sufficientsize to direct any liquid away from the rod extension.

An embodiment of the valve stem extension device of the presentinvention includes a cylindrical tube having an internal size sufficientto interfit over the stem extension device preferably the rod memberallowing the rod to rotate freely inside the tube. The tube has an upperend and a lower end and an attachment device structurally attaches thelower end of the tube to the valve body. A horizontal radial plate isstructurally attached to an outside surface of the upper end of the tubehaving at least two vertical holes extending through the radial plate,one hole positioned in relation to the full open position of the valveand one hole positioned in relation to the closed position of the valve.A locking plate is provided having an opening to interfit over the shapeon the upper end of the rod and further shaped to coupled with and movein conjunction with turning of the valve stem. The locking plate has ahole to align with the holes in the radial plate by turning the valvestem to the appropriate position. It is preferred that a locking devicebe provided to insert through the aligned holes in the radial plate andthe locking plate to prevent unauthorized rotation of the valve stem.The preferred attachment device includes an attachment plate to whichthe cylindrical tube is structurally attached, the plate having aplurality of holes through which bolt attachment devices attach theplate to the valve body. Preferred bolt attachment devices include apair of "U" bolts of a size and shape to interfit around the valve bodyand extend into four holes in the attachment plate to receive nuts tohold the attachment plate securely to the valve body. It is preferredthat a first vapor seal flexible elastomeric washer be compressedbetween the locking plate and the upper end of the cylindrical tube anda second vapor seal washer be provided that is sized to snugly fit overthe outside of the rod member and compressed between the attachmentplate and a rigid washer moving in conjunction with the rod member, suchas the stopping plate.

It is an object of the present invention to provide a valve stemextension for use on a fluid control valve which provides a high degreeof durability and near absolute assurance that the valve stem extensionwill not break or become inadvertently disengaged from the valve stem.

It is a further object of the present invention to provide a valve stemextension mechanism that can be effectively used with insulation packedaround the valve body and prevent liquid penetration along the stem intoand under the insulation.

It is an additional object of the present invention to provide a fluidcontrol valve stem extension which provides a duplicate stop mechanismto stop the valve stem from turning past either a full closure positionor a full open position.

It is a further object of the present invention to provide a valve stemextension system with a locking mechanism so that the valve stem may belocked into position to prevent unauthorized opening or closure of thevalve wherein the locking mechanism does not interfere with anyobstructions surrounding the valve body.

It is a further object of the present invention to provide a fluidcontrol valve locking mechanism having universal application fitting awide variety of fluid control valve types and sizes, and useful with awide variety of valve stem extension devices.

It is a particular object of the present invention to provide a fluidcontrol valve stem extension which may be attached to the valve stemafter the valve is on line, suing simple tools and procedures, but isessentially assured of permanent attachment during operation of thevalve.

It is a further object of the present invention to provide a lockingmechanism for a fluid control valve stem extension to preventunauthorized movement of the valve handle and in addition provideprotection from liquid invasion along the valve stem extension to thevalve body and the piping system.

It is an additional object of the present invention to provide a valvestem extension and locking mechanism with a vapor seal, sealing thevalve stem from the atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a fluid control valve stemextension device of the present invention.

FIG. 2 is a perspective, partially exploded view of a typical fluidcontrol valve.

FIG. 3 is an exploded view of the fluid control valve stem extensiondevice illustrated in FIG. 1.

FIG. 4 is a partially exploded view of a fluid control valve stemextension locking mechanism of the present invention.

FIG. 5 is a perspective view of the fluid control valve stem extensionlocking mechanism illustrated in FIG. 4 attached to a valve and a stemextension mechanism.

FIG. 6 is a partial vertical cross-sectional view taken from FIG. 5illustrating the fluid control valve stem extension locking mechanism.

FIG. 7 is a perspective view of a locking plate used in the fluidcontrol valve stem extension locking mechanism illustrated in FIGS. 5and 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

Fluid control valve stem extension 10 is illustrated in FIG. 1 attachedto valve 12 which includes valve body 14. Insulation 16 completelysurrounds and incases valve 12 except for hole 18 through which stemextension rod member 20 extends to a position outside and away frominsulation 16. Elastomeric washer 22 snugly interfits on rod 20 and isof sufficient width to distribute moisture away from hole 18 and preventit from leaking into and under insulation 16. Washer 22 is preferably ofa highly chemical resistant elastomeric polymer such as EDPM, marketedunder the trademark NORDEL, by E. I. DuPont DeNeMours, Inc., but may beconstructed of like quality polymers. Stem extension mechanism 10includes rod 20 which is engaged to an exposed end of the valve stem andheld in position with allen screw 24 sandwiching stop plate 26 whichincludes stop tab 28 which abuts stop 32 when valve 22 is closed andstop tab 30 which engages stop 32 when valve 12 is in the full openposition. At the upper end of rod extension 20, handle 34 is attachedwith nut 36 to shape 38 which is an exact duplicate of the exposed endof the exposed end of the valve stem hidden in this view.

In FIG. 2 typical fluid control valve 12 is illustrated showing exposedend 40 of the valve stem extending outwardly from valve body 14. End 40is rectangular in cross-section with threads cut into two oppositefaces. Turning exposed end 40 opens or closes valve 12. Handle 34 isattached to end 40 using nut 46 and lock washer 42. Attachment end 44 ofhandle 34 includes rectangular hole 46 which interfits over and engagesthe rectangular shape of exposed end 40 such that handle 34 provides thenecessary torque to turn the valve stem. Attachment end 44 also includestabs 48 and 50 which perform in the same fashion as tabs 28 and 30described above.

In FIG. 3, an exploded view of extension mechanism 10 illustrating rod20 interfitting over and threadably engaged to exposed end 40 of valve12. Lower end 52 of rod 20 is bored out with threads 54 matched to thethreads on exposed end 40. Two allen set screws 24 extend through thebody of rod 20 into the bored out end to engage the flat faces ofexposed end 40 which is in a general rectangular shaped threaded on twoends. Stop plate 26 includes tab stops 28 and 30 and rectangular hole 56which interfits over exposed end 40 to move in conjunction with thevalve stem. Thus, when engaged and attached securely, rod 20 and stopplate 26 move in conjunction with the valve stem of valve 12. At upperend 58 of extension rod 20 is located shape 60 which is an exactduplicate of exposed end 40 of the valve stem. In this case, shape 60includes rectangular extension shape 62 structurally attached and inthis case as an integral part of rod 20 extending in the same directionas the rod with threads 64 matching the threads on exposed ends 40.Handle 34 attaches to shape 60 using nut 36 and lock washer 42 asattachment end 44 interfits over rectangular extension 60 in the samefashion as it attached to exposed end 40 of the valve stem. Thus,attachment of handle 34 to valve stem extension 10 is at least as goodas it was to valve 12 itself. Stop plate 26 is an exact duplicate ofattachment end 44 of the handle. By duplicating the shape of theattachment hole and the tab positions handle 34 is stopped in the samefashion as it was when it was attached directly to valve 12.

In FIG. 4, locking mechanism 70 is illustrated before it is attached tovalve 112. Locking mechanism 70 includes cylindrical tube 12 which iswelded to attachment plate 74 having a plurality of holes includingholes set 76 and holes set 78. Elongated holes 76 are positioned toreceive "U" bolts 80 which]extend through pairs of holes 76y andattached with nuts 82. Holes 78 are positioned to receive bolts whichthreadably engage directly into holes commonly provided in valve bodycasings to attach meters and other devices to the valves. In many cases,these threaded holes in the casing may be easily used to attachattachment plate 74 to the valve body. Cylindrical tube 72 has insidearea cavity 84 which extends the entire length of tube 72 and opensthrough attachment plate 74 below of a size that permits a fluid controlvalve stem extension device to freely turn inside the cylindrical tube.Radial plate 86 is horizontally welded to tube 72 proximate the upperend and extends around the outside surface of tube 72 a sufficientdistance to position holes 88 and 90 which relate to the full openposition of the valve and the full closed position to the valve,respectively.

In FIG. 5, locking mechanism 70 is attached through "U" bolts 80 tovalve 112. The threads on the ends of "U" bolts 80 may be easily crushedto prevent removal of nuts 82 after locking mechanism 70 is securelyattach to prevent unauthorized removal of the locking mechanism. Whenthe locking mechanism is to be removed by authorized personnel, an easybut time consuming rethreading of the ends of the "U" bolts will allowremoval of nuts 82. In the alternative, special locking nuts may be usedon the ends of the "U" bolts to prevent unauthorized removal of thelocking mechanism. Wheel 114 is attached to valve stem extension member116 with nut 118, the entire movement of that mechanism being free torotate within cylindrical tube 72. Locking plate 120, mostly obscured inthis view, is attached and held with nut 118 to move in conjunction withvalve stem extension 116 such that it rotates horizontally in relationto horizontal radial plate 86.

In FIG. 6, locking mechanism 70 is shown attached through "U" bolts 80to valve 112 which includes valve stem end 122 on which is attachedvalve stem extension 124 by threaded engagement and allen bolts 126.Stop plate 128 duplicates the shape including the downward extending tabto that from turning wheel 114. Stop plate 128 includes a hole shapewhich interfits over valve stem end 122 so that it moves in conjunctionwith the valve stem to abut stops molded in the body of valve 112relating to the open position of the valve and a full closed position ofthe valve. At the upper end of locking mechanism 70, locking plate 120is sandwiched and held in position by nut 118 to move in conjunctionwith stem extension 124 and the valve stem of valve 112. Thus, whenvalve extension 124 is rotated, lock plate 120 is also rotated such thathole 132 aligns with either hole 88 or hole 90 which relate to eitherthe full open position of valve 112 or the full closed position of valve112 respectively. Flexible rubber washer 92 snugly interfits aroundcylinder 72 and operates in the same fashion as elastomeric polymericwasher 22 illustrated in FIG. 1. Flexible "O" ring rubber washer 94 issnugly interfitted over valve extension rod 124 and prevents waterintrusion between stem extension rod 124 and the inside of cylindricaltube 72. Washer "O" ring 94 snugly interfits around extension rod 124and is compressed under locking plate 120 against the top edge of tube72. Stop tab 130 is either broken off or bent upwardly (as shown) so asto not interfere with the locking mechanism. Alignment of the holesallows insertion of a locking mechanism, such as a keyed pad lock toengage hole 132 and either holes 88 or 90 depending upon the intendedlocked position of valve 114. Flexible washer "O" ring 75 interfitsaround extension rod 124 and is pressurably sealed between stop plate128 and the bottom surface of attachment plate 74. Whenever a part is tomove in conjunction with the valve stem or its extension, the shape ofthe exposed end of the stem or its extension is such that if a memberwith a hole of that shape is interfitted over the end and the member isturned the valve stem will turn or visa versa. Where the end of thevalve stem is not threaded a connecting member is added with a lower endinterlocking with the exposed end and having a threaded upper end withflat faces to receive the set screws. In some cases it is not necessaryto reproduce the exposed end exactly on the upper end of the rod memberas it only need be reproduced sufficiently to allow secure fastening ofthe valve turning device. In FIG. 7, locking plate 120 shows therelative position of hole 132 and attachment hole 134 which is in ageneral rectangular shape to interfit over extension end 116 so that itwill move in conjunction with extension 124.

The combination of washers 75 and 94 provides a vapor seal of theextension locking device.

While this invention has been described with reference to the specificembodiments disclosed herein, it is not confined to the details setforth and the patient is intended to include modifications and changeswhich may come within and extend from the following claims.

I claim:
 1. In a fluid control ball or plug valve having a body, a valvestem having an exposed end on which a valve turning means detachablyattaches to rotate the valve stem to adjust fluid flow through thevalve, and a stopping device structurally attached to the valve turningmeans stopping rotation of the valve stem in a full open position toopen the valve and in a closed position to close the valve, a valve stemextension device comprising:(a) a rod member having an upper end and ofsufficient length to position the valve turning means attached to theupper end at a position movably free of obstruction; (b) a lower end ofthe rod member having a threaded cylindrical bore opening to the lowerend having threads mating to the exposed end of the valve stem, (c) twoset screws threadably engaged through horizontal holes in the side ofthe rod member opening into the bore opening to bear on the end of thestem mated into the bore opening, and (d) the upper end of the rod of ashape to duplicate the cross sectional shape of the exposed end of thevalve stem, (e) a plate having a hole of a shape to interfit over theexposed end of the valve stem and coupled to move with turning of thevalve stem, the plate comprising a stop means duplicating the functionof the stopping device, (f) a cylindrical tube having an internal sizesufficient to interfit over the rod member allowing the rod to rotatefreely inside the tube, the tube having an upper end and a lower end,(g) an attachment means structurally attached to the lower end of thetube to attach the tube to the valve body, (h) a horizontal radial platestructurally attached to an outside surface of the upper end of thetube, having at least two vertical holes extending through the radialplate, a first hole positioned in relation to the full open position ofthe valve and a second hole positioned in relation to the full closedposition of the valve, and (i) a locking plate having an opening tointerfit over the shape on the upper end of the rod, and shaped tocouple with and move in conjunction with turning of the valve stem andhaving a hole to align with the first hole in the radial plate when thevalve stem is in the full open position and with the second hole whenthe valve stem is in the full closed position.
 2. The valve stemextension device of claim 1 wherein the attachment means comprises anattachment plate having a plurality of holes through which boltattachment means attach the plate to the valve body.
 3. The valve stemextension device of claim 1 wherein the exposed end of the stem hasrectangular cross-section and is threaded on at least two vertical sidesand has at least one flat side.
 4. The valve stem extension device ofclaim 1 wherein the exposed end of the stem has two flat vertical sidesand there are two set screws engaged through the side of the rod to bearon the flat sides of the exposed end of the valve stem.
 5. The valvestem extension device of claim 1 wherein a flexible elastomeric washersnugly interfits onto the rod member.
 6. A locking device on a valvestem extension for a ball or plug fluid control valve interfitted with astem extension to place a valve turning means to turn the valve stem ata position movably free of obstruction comprising:(a) a cylindrical tubehaving an internal size sufficient to interfit over the valve stemextension allowing the valve stem extension to rotate freely inside thetube, the tube having an upper end and a lower end, (b) an attachmentmeans structurally attached to the lower end of the tube to attach thetube to a body of the valve, (c) a horizontal radial plate structurallyattached to an outside surface of the upper end of the tube, having atleast two vertical holes extending through the radial plate, one holepositioned in relation to a full open position of the valve and one holepositioned in relation to a full closed position of the valve, and (d) alocking plate having an opening to interfit over the shape on the upperend of the rod, and shaped to couple with and move in conjunction withturning of the valve stem extension and having a hole to align witheither of the holes in the radial plate by turning the valve stemextension.
 7. The locking device of claim 6 further comprising a lockingmeans inserted through the aligned holes in the radial plate and thelocking plate to prevent unauthorized rotation of the valve stemextension.
 8. The locking device of claim 6 wherein the attachment meanscomprises an attachment plate having a plurality of holes through whichbolt attachment means attaches the plate to the valve body.
 9. Thelocking device of claim 8 wherein the bolt attachment means comprises apair of "U" bolts of a size and shape to interfit around the valve bodyand extend into four holes in the attachment plate to receive nuts tohold the attachment plate securely to the valve body.
 10. The lockingdevice of claim 6 wherein a flexible elastomeric washer snugly interfitsover the outside of the cylindrical tube between the radial plate andthe attachment plate.
 11. The valve stem extension device of claim 6wherein a first vapor seal washer is compressed between the lockingplate of the upper end of the cylindrical tube and a second vapor sealwasher snugly interfits around the rod member and is compressed betweenan attachment plate of the attachment means and rigid washer interlockedat the lower end and moving in conjunction with the rod washer.
 12. Thevalve stem extension device of claim 11 wherein the rigid washer is aplate comprising a stop means stopping rotation of the valve stem in afull open position to open the valve and in a closed position to closethe valve, the plate further comprising a hole of a shape to interfitover the exposed end of the valve stem and coupled to move with turningof the valve stem.
 13. A locking device on a valve stem extension for aball or plug fluid control valve interfitted with a stem extension toplace a valve turning means to turn the valve stem at a position movablyfree of obstruction comprising:(a) a cylindrical tube having an internalsize sufficient to interfit over the valve stem extension allowing thevalve stem extension to rotate freely inside the tube, the tube havingan upper end and a lower end, (b) an attachment means structurallyattached to the lower end of the tube to attach the tube to a body ofthe valve comprising an attachment plate having a plurality of holesthrough which bolt attachment means attaches the plate to the valvebody, (c) a horizontal radial plate structurally attached to an outsidesurface of the upper end of the tube, having at least two vertical holesextending through the radial plate, one hole positioned in relation to afull open position of the valve and one hole positioned in relation to afull closed position of the valve, and (d) a locking plate having anopening to interfit over the shape on the upper end of the rod, andshaped to couple with and move in conjunction with turning of the valvestem extension and having a hole to align with either of the holes inthe radial plate by turning the valve stem extension.
 14. The device ofclaim 13 wherein the fluid control ball or plug valve comprises a body,a valve stem having an exposed end on which a valve turning meansdetachably attaches to rotate the valve stem to adjust fluid flowthrough the valve, and a stopping device stopping rotation of the valvestem in a full open position to open the valve in a closed position toclose the valve, and the valve stem extension device comprises:(a) a rodmember having an upper end and of sufficient length to position thevalve turning means attached to the upper end at a position movably freeof obstruction, (b) a lower end of the rod member having a threadedcylindrical bore opening to the lower end having threads mating to theexposed end of the valve stem, (c) two set screws threadably engagedthrough horizontal holes in the side of the rod member opening into thebore opening to bear on the end of the stem mated into the bore opening,and (d) the upper end of the rod of a shape to duplicate the crosssectional shape of the exposed end of the valve stem.
 15. The device ofclaim 14 wherein the stopping device is structurally attached to thevalve turning means, the valve stem extension device further comprisinga plate having a hole of a shape to interfit over the exposed end of thevalve stem and coupled to move with turning of the valve stem, the platecomprising a stop means duplicating the function of the stopping device.16. The valve stem extension device of claim 13 wherein the bolt meanscomprises a pair of "U" bolts of a size and shape to interfit around thevalve body and extend into four holes in the attachment plate to receivenuts to hold the attachment plate securely to the valve body.
 17. Thevalve stem extension device of claim 13 wherein a flexible elastomericwasher snugly interfits over the outside of the cylindrical tube betweenthe radial plate and the attachment plate.
 18. The valve stem extensiondevice of claim 13 wherein a first vapor seal washer is composed betweenthe locking plate and the upper end of the cylindrical tube and a secondvapor seal washer snugly interfits around the rod member and iscompressed between an attachment plate of the attachment means and rigidwasher interlocked at the lower end and moving in conjunction with therod member.
 19. The device of claim 13 wherein the valve stem extensioncomprises:(a) a rod member having an upper end and having sufficientlength to position a valve turning means attached to the upper end at aposition movably free of obstruction, (b) a lower end of the rod memberhaving a threaded cylindrical bore opening to the lower end havingthreads mating to the exposed end of the valve stem, (c) two set screwsthreadably engaged through horizontal holes in the side of the rodmember opening into the bore opening to bear on the end of the stemmated into the bore opening, (d) the upper end of the rod of a shape toduplicate the cross-sectional shape of the exposed end of the valvestem, and (e) a plate having a hole of a shape to interfit over theexposed end of the valve stem and coupled to move with turning of thevalve stem, the plate comprising a stop means stopping rotation of thevalve stem in a full open position to open the valve and in a closedposition to close the valve.
 20. The device of claim 19 wherein theexposed end of the valve stem has a rectangular cross-section and isthreaded on at least two vertical sides and has at least two flat sides.21. The device of claim 19 wherein the exposed end of the stem ahs twoflat vertical sides and the set screws engage through the side of therod bear on the flat sides of the exposed end of the valve stem.
 22. Thedevice of claim 19 wherein the exposed end of the stem is not threadedand the valve stem extension device further comprises a mating means toattach at one end to the exposed end of valve stem and have a threadedrectangular projection at the other end to interconnect with the rodmember.
 23. The device of claim 19 wherein a flexible elastomeric washersnugly interfits onto the rod member.
 24. The locking device of claim 13further comprising a locking means inserted through the aligned holes inthe radial plate and the locking plate to prevent unauthorized rotationof the valve stem extension.
 25. The locking device of claim 13 whereinthe bolt attachment means comprises a pair of "U" bolts of a size andshape to interfit around the valve body and extend into four holes inthe attachment plate to receive nuts to hold the attachment platesecurely to the valve body.
 26. The locking device of claim 13 wherein aflexible elastomeric washer snugly interfits over the outside of thecylindrical tube between the radial plate and the attachment plate. 27.The valve stem extension device of claim 13 wherein a first vapor sealwasher is compressed between the locking plate and the upper end of thecylindrical tube and a second vapor seal washer snugly interfits aroundthe rod member and is compressed between an attachment plate of theattachment means and rigid washer interlocked at the lower end andmoving in conjunction with the rod member.
 28. The valve stem extensiondevice of claim 27 wherein the rigid washer is a plate comprising a stopmeans stopping rotation of the valve stem in a full open position toopen the valve and in a closed position to close the valve, the platefurther comprising a hole of a shape to interfit over the exposed end ofthe valve stem and coupled to move with turning of the valve stem.